1. Field of the Invention
The present invention relates generally to a method and apparatus for recapping or retreading tires.
2. Description of the Prior Art
Worn tires are generally recapped using one of several known techniques. Typically, the tread or outer circumference of the worn tire casing must first be buffed down. If hot cure methods are being used, the buffed tire casing and new tread rubber are placed in a mold, and the new tread molded onto the casing.
Precure or cold cure techniques are more commonly used since they produce a longer wearing retreaded tire. Following these methods a strip of retread rubber or material is cut from a roll and mounted to the outer surface of the buffed tire casing by an adhesive and cushion gum. An envelope formed by an innertube, flap and metal rim is then mounted to the tire. The innertube is positioned about the interior circumference of the tire, while the flap is draped over the exterior circumference. The flap and innertube are sealed together on opposite sides of the tire near the beads by the rim, to form an airtight envelope surrounding the tire. The innertube is then inflated, and the tire positioned in a curing oven. Air is evacuated from the flap through a valve coupled to a vacuum pump by a hose. The tire is then cured in the oven by heating it under pressure.
Cold cure techniques involving an envelope formed by a rim, innertube, and flap are difficult and time consuming to implement. The rims are heavy, and a number of different sizes are needed to correspond to the size of a tire being retreaded. The flaps and innertubes often fatigue and fail, further adding to the expenses involved in this method.
It is evident that there is a continuing need for improved procedures for recapping tires. An apparatus and method which reduce the expense and difficulty associated with the envelope currently used with cold cure techniques is desired.